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First time accepted submitter tonyt3 writes "Scientists plan on conducting an unusual climate experiment at a Norfolk airfield next month. They plan to spray water into the air about 20 km high to mimic volcanic particles, hoping that their findings could lead to a solution to global warming. From the article: 'Pouring 10 million tonnes of material into the stratosphere each using 10 to 20 giant balloons could achieve a 2C global drop in temperature, the scientists believe. Sulphate emissions from the Mount Pinatubo eruption in the Philippines in June 1991 reduced world temperature by 0.5C for two years.'"

Considering a column of water 10m high results in one atmosphere of pressure, a 1 km column would need a pipe capable of holding a pressure of 1,470PSI while still being light enough to be suspended by balloons! This is going to take some serious engineering mojo, and all because the Earth's average temperature has increased from 288.0K to 288.8 over the last 150 years.

TFA is still a bit confusing. At one point they are talking about 20 pipes, each of them being 1 km long, and at another point someone starts talking about the pressure needed to move the water 20 km up.

But this experiment isn't trying to use water vapor to provide a cooling effect - the ultimate plan is to use some other material. The test uses water 'cause it's cheap, abundant and environmentally benign. The "real" plan might use water as a carrier agent for whatever it is they actually send up.=Smidge=

Water is much more potent than CO2, but it does not cause climate forcing (in the sane temperature range, anyway). I.e. water vapor exists in the equilibrium condition - put more some additional vapor into the air and it will quite soon (hours to days) condense into water. So the more water you put into the atmosphere - the harder it'll going to rain down a few days after.

CO2 doesn't work that way. If you put it into the atmosphere - it just stays there (modulo CO2 sinks). It's not an equilibrium system (well, it is, but with very large reaction times) - more CO2 in the atmosphere will just give you more CO2 in the atmosphere.

Now, stratospheric water is yet another thing. It'll exist a a very fine snow ice particles (I won't call it 'snow' for the don't look like it) and in fact have the opposite effect - they reflect sunlight back into space. The greenhouse effect of stratospheric gases is mostly irrelevant, because 'stratosphere' is just another name for 'almost a hard vacuum'. AND stratosphere doesn't mix a lot with troposphere, so these ice particles are going to persist for a fair amount of time (probably months).

Well, when someone implies that climate scientists don't know how to account for water vapor (which guess what, they do) AND is dismissive of those who are at least not fuckheaded enough to dismiss the conclusions of those much smarter than themselves, then I consider it my duty to call that person out as being a dripping festering cunt. So any rage problem I have might just be attributable to the large population of cuntdom out there.

Another failure of Slashdot editing in basic facts checking. The article states 1 km. The stratosphere is between 10 and 50 km, so 1,000 km would go well above that. The nominal edge of the atmosphere is about 600 km. Someone got a little too excited with the zeros, methinks.

Maybe that's the plan. Form an ice ring around the earth by building on satellite orbits, and then the solar winds will blow cool...space wind at the planet. Just like the old ice in front of a fan trick!

Presumably the water they do spray will increase the amount of water vapour in the atmosphere, which is bad, so you wouldn't want to build the working model using water. But for a test water droplets have the advantage of being well accepted as non-toxic.

Right, there's a significant difference between water vapour and water aerosols, which is what this experiment is about. The second thing is that they are mainly interested in testing whether they can pump the stuff that high, instead of the climatological effects of that. (Which realistically ought to be negligible for a test this small.)

This is just a first test of the technology. If they were really going to use this for climate engineering, they'd use "clay, salts or metallic oxides suspended in liquid" (according to TFA) to reflect some sunlight back into space before it hits the earth.

As you can imagine, just figuring out whether you can pump millions of kilograms of stuff 1,000 meters into the air (not 1,000 km, as the submitter wrote) is an open question. Their ultimate goal is to get it 20 km up. For the first test, you use what's cheap: water.

The water itself is a greenhouse gas, but water molecules condense and fall as rain. It quickly returns to the existing equilibrium. The goal is to put up particles that would stay there for a while. Unlike water, they don't condense and fall out as quickly.

Before it fell, the water would reduce sunlight a bit. Water vapor is a greenhouse gas, but water in clouds isn't vapor; it's condensed droplets. Those droplets can reflect light; that's why cloudy days are dark. The goal isn't to produce water clouds, which would only be temporary and would be too much darkening. The goal is to put up enough particulates to get a slight reduction of incident light without having to continually pump new particles into the atmosphere.

(Note: I'm not crazy about geoengineering as a solution to climate change, but the experiment is still interesting.)

Yes. Because changing the albedo for the total surface area of all the roofs in all the world would have any significant effect on a global scale... (hint: it wouldn't)

You'll end up with lower cooling bills in the summer, and higher heating bills in the winter. City temperatures will drop by a couple degrees, and in turn that will cause some localized changes in weather patterns, but that's about it.

The quantity of water vapor in the troposphere averages around 1% or 10,000 ppmv as compared to 390 ppmv for CO2 which means there is around 25 times as much water vapor in the atmosphere as there is CO2. So, from the Wikipedia article water vapor is responsible for 36-72% of the greenhouse effect and CO2 is responsible for 9-26% of the greenhouse effect. So water vapor is responsible for 3-4 times as much greenhouse warming as CO2 despite being 25 times more prevalent.

Except if such a positive feedback loop worked as you suggest, we would be running our ACs a lot harder than we are currently. Many global warming models had predicted changes over the last ten years several times what they actually were, misjudging the effect this feedback loop would have.

The Sun provides the incoming energy. Without the greenhouse gases in the atmosphere blocking some of the outgoing IR radiation the average temperature on the surface of the Earth would be around 0F (-17.7C) instead of 58F.

I know, right? And just look at those morons in New Orleans who complained a few years back about that hurricane. It was way less than 1% of the water in the Atlantic! What harm could it have done? Same goes for people who get stabbed -- the knife wound severs less than 1% of the blood vessels in your body, so what's the big deal?

Question.... if you have two one hundred pound weights on opposite sides of a scale, and add one pound to one of them, what happens?

You think that a third of CO2 in the atmosphere comes from human activity? You think that what we do is more substantial than an entire world of decaying organic matter and volcanic activity? Decomposing organics alone accounts for more than four times more than human activity (at least according to Wikipedia, which I don't necessarily trust but I've been searching for the better part of a hour for hard numbers for world biogenic CO2 emissions and found nothing), which if you can do basic math already inv

For thousands of years since the end of the last glaciation around 10,000 years ago the CO2 level in the atmosphere hovered around 280 ppmv. Every year, tracking the seasons, the level fluctuated about 10 ppmv going down as plants grew in the northern hemisphere spring/summer and going back up as stuff decayed in the northern hemisphere autumn/winter. It's all part of the carbon cycle which holds a balance of carbon between the atmosphere, hydrosphere and biosphere (with the geosphere playing a minor role

Greenhouse gases raise Earth's temperature from from 260 K to 288 K. If CO2 is responsible for 10% of that, it's responsible for a 2.8 K temperature change. If we assume the temperature change is linear with the amount of CO2 a doubling of the CO2 in the Earth's atmosphere will result in a 2.8 K temperature increase. Which is within the range of temperature change climate scientists predict for a doubling of the CO2 in Earth's atmosphere.

It's also generally accepted that these are not independent, since increases in CO2, CH4, and O3 increase the temperature, which increases the water vapor: "The average residence time of a water molecule in the atmosphere is only about nine days, compared to years or centuries for other greenhouse gases such as CH4 and CO2. Thus, water vapor responds to and amplifies effects of the other greenhouse gases."

(2) "and that the amount generated by human activity is further less than 10% of that CO2."
The CO2 in the atmosphere has increased from 270-280 ppm a century ago to 390 ppm today (and it was down to 180 ppm in the last ice age). 390/280 = 40% increase. And, before you say that not all the 110 ppm increase is due to human activity, I submit this graph showing that CO2 levels over the past 600,000 years have never been above 300 ppm until the 20th century ( http://static-www.icr.org/i/articles/af/does_carbon_dioxide_fig3new.jpg [icr.org] )

You know: I'd think there was a lot more to climate change denial if the facts presented by climate deniers weren't almost always wrong.

I would be interested to know, though, how they think this would lower the temperature - for example: if water vapor at different elevations have different effects.

Argh, blargh. I really hate it when people are so sure about completely wrong science, especially as their aggressive misinformation is being exploited by civilizational sociopaths.

I am usually nice on the internet, but this will be an exception.

Slashdot posters usually have some knowledge of Newtonian mechanics 101 and will rightly laugh at those who don't believe in say, conservation of momentum.

Well, this is the same level of blunder, so here goes the explanation, as nice as I can make it without wanting to strangle internet ignoramuses.

Yes, water is a greenhouse gas, and yes every climate scientist since 1900 or whatever has known this, and there has never been any conspiracy to "suppress" this, especially given that the water cycle is at the core of every weather and climate model and observational data set.

And human "emissions" of water are completely and totally irrelevant (say like the post above) because the planet is in statistical equilibrium with those very large sources of water known as "oceans". Water, namely vapor and clouds, are *feedbacks* with timescales of two weeks, vs dozens to thousands of years for carbon dioxide. For example, if you magically took all the water out of the atmosphere, how long would it take to get back to normal? A few weeks. If you magically saturated the atmosphere completely with water, how long would it take to get back to normal? A few weeks. If you magically took all the CO2 out of the atmosphere, how long would it take to get back to normal? Many, many millions of years.

The amount of water in the atmosphere is determined in large measure, by,what---yes the temperature! Hotter air absorbs more water, and yes, the water vapor will add its own greenhouse effect. The water vapor amplifies global warming which was induced by the excess of long-lived greenhouse gases like CO2 (and others) introduced by human activity. (Clouds are less certain---they may go both ways for heating/cooling in various cases, this is a complex area of current study---but the base level effect of vapor {clear, humid air} is undisputed and significant)

The scientists who have been studying this for decades know what they're talking about.

Don't bother. This is about the only thing tmosley posts over and over. He is absolutely fact resistant, preferring to wallow in his own ignorance which he manages to twist into preceived superiority and then, to top it off, into a persecution complex. You know, that world wide conspiracy of scientists hooked on the mythical "funding" being out for all of us.

To claim that water vapor is an issue or that humans could have any effect on water vapor levels in the atmosphere (except in some local situations) it as silly as those guys who claim the CO2 you exhale is going to become an issue. Continuing to bring it up just shows your ignorance.

Sometimes you're on a crowded bus and you can tell that the person next to you decided they didn't have time to actually get clean, but thought they could mask their odor with deoderant. Unfortunately, in some cases, what you get is a retch-inducing mixture of BO and deodeo.

Solutions like this to the climate issue remind me of those folks on the bus. If there's a real problem and if there are real things we can do to address the cause, let's do them. If, instead, we don't address the cause but do something else to mask the issue, then it seems likely that we'll just end up with an even bigger mess. I can just imagine scientists from another planet examining the burnt out husk of Earth and saying, "There's no life there; the atmosphere is an unlivable mix of carbon dioxide and sulphates!"

You've unwittingly described the climate that gave rise to life in the first place. It wasn't until organisms started photosynthesis that a new type of life came along and radically altered the atmosphere, killing almost everything else that came before it in the Oxygen Catastrophe of the Siderian. Which in turn allowed all the animal life we know to come to exist.

This is the fundamental problem with green ideologues, they think that the biosphere is static and that life is impossible if it changes. You need to wrap your head around some facts. Mass extinctions created the current biosphere. If you think mass extinctions are bad, you must by extension think that the current biosphere you currently hold next to sacred is also ultimately a perversion of the state of life before said extinctions.

Life can spring back from virtually nothing. During the greatest mass extinction, 90% of ocean-dwelling species perished completely. Have you noticed how they're not still empty? More importantly, have you noticed how there are a lot more species in the oceans now than in the Permian? Over time, biodiversity has always increased, regardless of how severe any event has been over short periods.

The Chinese have a saying: 'Jiu de bu qu xin de bu lai' which means 'If old things don't go, new things will never come.'

This is the fundamental problem with green ideologues, they think that the biosphere is static and that life is impossible if it changes.

This is the fundamental problem with gigantic bipedal primates whose capacity for rational thought isn't as strong as their desire not to change their favorite habits; they think that when the biosphere changes, they'll be among the chosen species to survive.

You are way, way huger than anything that survived the greatest mass extinction, and this is not a fat-guy-in-mom's-basement joke. No human would have survived that event.

Humans are the cockroaches of large mammals. We can eat anything and live anywhere and can even withstand (as a population) large amounts of toxins and pathogens. More importantly, we can solve problems rationally and move or convert resources in innumerable ways. Mankind is as close to extinction-proof as any large animal can be.

So you don't mind living in shitty conditions, breathing toxins and pathogens, and enduring extreme climates? Maybe you don't mind living in misery, or perhaps in a completely sterile and artificial environment made of concrete, but the rest of us do. We want to live somewhere where we can go outside, breathe fresh air, enjoy nature, at least part of the time.

The other problem with global warming is that it results in rising sea levels. Something like 90% of the earth's population lives at sea level; ris

Word... offsetting global warming by global dimming doesn't sound all that great of a deal.

That's trading useful energy (sunlight reflected back to space by aerosol pollution) for useless energy (more heat energy retained by greenhouse gases). The temperature might end up being the same, but the the entropy is higher.

Not an ideal way of saving the planet:-P It's bad enough that we're burning up all the fossil fuels stored from the solar energy collected by plants over the eons, but then there will be le

Huh? Maybe I'm forgetting my freshman chemistry, but the energy coming from the sun is mostly heat, so if we retain more heat (with greenhouse gases), but compensate for it by reflecting more energy from the sun, doesn't that result in the same entropy?

Plants don't photosynthesize heat, they need that electromagnetic radiation that's being reflected back out to space, You can't really do much with thermal heat, unless you also have a cold place so you can run some sort of engine off of the temperature gradient. But then after that the hot place is less hot, the cold place is less cold, and you come closer to heat death. So we should maybe sort of be a little bit worried about the ice caps melting, because then we won't have so many cold areas to drive

I think an immediate drop of 2c in global temperature would be a severe problem, actually. Our fear of global warming shouldn't cause us to over-react. In general, a warmer globe is better than a cooler globe... and long term, global cooling is a more existential threat than global warming. More inevitable, too.

That's no profit, that's redistribution. It sounds very nice on theory, but there is one little problem - the people who decide how to spend tend to give it to their friends and relatives 120% of the time (if you include debt). And these friends and relatives are not in the R&D business.

I'm glad scientists are working on ideas like this. The reality is that we, the human race, are not going to stop burning fossil fuels. We'd best get on with figuring out how to deal with the resulting problems rather than continue dreaming that everyone is going to agree to stop.

It's like a smoker using air filters to clean up second hand smoke. Sure it may reduce the consequences of their actions, but it doesn't negate the fact that the addiction is the source of their problem.

That being said, I don't want to dismiss their research altogether. The data will probably be useful for improving climate models and we may just have to resort to such tactics since we've been doing relatively little about climate change even though we've been aware of the issue for decades.

Well the people who deny global warming ultimately want free reign to pollute the global Commons without consequence. It's tragic.

This option, at least, doesn't involve us simultaneously convincing everyone on the planet to not be selfish bastards with shared resources. "You think it's okay to dump whatever crap you want to into the sky for a profit, consequences by damned? Well then you certainly can't stop us from shooting our own stuff into the sky and blocking out the sun a little."

What those idiots don't seem to realize, is that the effects of volcanic eruptions and the associated decline of global temperatures has always had catastrophic consequences. Be it the year without summer 1816 because of the Mt. Tambora [wikipedia.org] eruption, the famines of 536 [wikipedia.org] or the the Hatepe Eruption of 180AD [wikipedia.org].

What a pathetic strawman. "warming is bad mkay"? Are you for real? Go read some actual literature from climate scientists, not the caricature offered up by propaganda machines funded by parties with undisclosed conflicts of interest.

A true climate scientist would not say "warming is bad", but instead might say something more like there is a very narrow range of global climates in which humanity has prospered, and climates which are too hot or too cold could have devastating consequences on human societie

We are talking about the idea of duplicating the effects of a volcanic eruption so as to "counter"... warming. Not ocean acidification. Not cooling in some regions vs warming in others (climate change, indeed, is different in different parts of the globe). No. Particulates limiting the amount of sun that reaches the surface leads invariably to cooling.

Presumably a balloon would not even need to be detonated - it could be made to explode from the pressure changes in the atmosphere as it ascends - although it may not release its particles at a desirable altitude in that model. Then there is the release of whatever gas was used (helium) in the balloon, although I don't know what effect that would have on the atmosphere.

Naw just a sense of humor over a statement made by a person using a computer whose very creation involved making green house gasses, that uses power that is probably from a grid that produces green house gasses.

Potable water is way too precious a resource to be feasible for such an 'experimental' (read: crack-pot) idea:

FTFA:

''We're going to try to pump tap water to a height of one kilometre through a pipe as a test of the technology.''...Pouring 10 million tonnes of material into the stratosphere each using 10 to 20 giant balloons could achieve a 2C global drop in temperature, the scientists believe.

also:

Experts believe particles of clay, salts or metallic oxides suspended in liquid would prove more effective than the sulphates produced by real volcanoes.

So, why aren't they starting with salt water, again? If their experiment achieves everything they ever hoped for, they're still going to have to do it all over again with sea water anyways...and see if the resulting salt-water rains affect anything (gee, you think it would?) Or they're going to have to start building some big-ass desalination plants...and I just bet they won't be solar-p

On the bright side if they build the desalination plants and manage to run them off solar power, the technology could be used to give more people access to drinking water.

Or, as would be more likely, they'll only build half the desalination capacity they need, and 'appropriate' the rest from existing plants to save money...although, to be fair, I suppose this scheme may also double as a fresh water transportation medium, since one would expect rain downwind of the balloons...if they set it up correctly and prevailing winds are more or less constant, that is.

This is a small scale test, they are not pumping 10 M m3 at this point, that is the final geoengineering scale.

Please read all TFA or just do the normal thing and ignore and speculate. Halfway in between is just silly.

Yess...but my actual point was that if they (likely) won't be able to use fresh water at the geoengineering scale, why on earth are they using it for testing? Shouldn't they be testing with the final resource that they would expect to be using, especially if dissolved salts are *believed* to be more effective? If this does prove out and they do move ahead using fresh water...well, they will have to generate a massive amount of fresh water first, which likely won't be achieved using energy from renewable r

Potable water is way too precious a resource to be feasible for such an 'experimental' (read: crack-pot) idea:

FTFA:

No.

Just like food there is an excess of it on earth compared to the number of people. The reason some people are without water and food is just because of logistics.In the area where I live it is a lot easier and cheaper to use potable water. (More or less walking distance from a large fresh water lake with about 153 billion cubic meters of fresh water. The 10 million cubic meters is a drop in the ocean compared to that.)

Transporting that amount of salt water here would not only be very expensive, the salt would also cause a lot of problems.

Couldn't we achieve the same effect, if all 5 billion+ of us on the planet go outside and blow a raspberry http://en.wikipedia.org/wiki/Blowing_a_raspberry [wikipedia.org] ? Ya know, like, spraying water particles in the air? It would certainly be a lot of fun if we had a World Bronx Cheer Day.

Yes. The animals and birds and glaciers don't respond to human biases, and what they're doing is clear indication of warming.

The denialists are getting worse---they started out saying "there's no warming" (after the 1990's volcano had some temporary cooling), and then when the warming got clear, they said "well we don't know that people are responsible" (after all it could be magic fairys who just happen to change infrared emissivity of the atmosphere in exactly the way predicted by liberal-infected chemist

Any scientist who is a proponent of AGW theory is pure as the driven snow, honest, no ulterior motives, and with no allegience to those writing the paychecks. His goal is purely the science.

Any scientist who is a skeptic of AGW theory is an evil troll, dishonest, greedy, wants to destroy the Earth with his SUV and other wasteful habits, and will produce any result those who are funding him dictate.

At least that's how it appears the true believers see it, the ones who have lost the ability to be skeptical.

Except the idea is not to lift tons of stuff, but a pipe that pumps the stuff up and sprays it. The balloon only needs to lift the pipe and the fluid in the pipe at any time, not the total of the fluid pumped up over the course of the project.

You're right, helium is too precious to be used for more than the initial tests. Once they get into unmanned platforms far out to sea, there is really no reason not to use hydrogen. It should be possible to arrange it so that if there is an fire nearly everything but the envelope itself can be salvaged.

The amount of lift needed will less than 100,000 tonnes. A 50cm diameter x 20km column of water weighs less than 4000mt. The pipe will have to have some serious walls, though - that's nearly 2000 bar just fro

The answer; a lot of coal would be needed to run this programThe uncomfortable truth; relatively little coal would be needed to run this program.

The world consumed 4.74*10^20 joules of energy in 2008, it is safe to say that at least half that was carbon based.the simple equation m*g*h say that operating at 100% efficiency, the pumps would need 1.96*10^15 joules per year to pump 10 million tonnes of material 20 km high.

Now say the pumps were only 10% efficient, and assume my 50% carbon based energy claim is

Pipe friction losses will more than double the energy needed. OTOH it should be able to offset a bit of that with wind. Solar would only offer a percent or two of the energy needed, even if it covered the whole upper surface of the balloon, and the weight and expense would make it impractical.

Harnessing the wind could potentially be better, given the high and relatively constant winds in the stratosphere. Because of the nearly 20x lower density, though, the ~15m/s (34mph) median stratospheric wind speed's a

We're already seeing the fallout of this ideology in the form of mandatory burning of food in Europe and the USA as biofuels. Not to mention that this debate is hiding the fact that the developing countries are catching up [wordpress.com] to our economies while the production of energy resources cannot be expanded indefinitely. In other words: The industrialized countries will have to share those resources with the developing countries, which is something they are perfectly unwilling to admit to the public. And n

The only reason why we 'struggle' for water, at least in some places is because no one wants to build desal plants. This really holds true in places like California. Well whatever, the leftist state full of nimbyists that it is.